Final answer:
Intermediate Metal Conduit (IMC) has a wall thickness that falls between RMC and EMT. It offers a lighter and often less expensive solution while still providing good physical protection for electrical wires.
Step-by-step explanation:
The conduit that has a wall thickness less than that of RMC (Rigid Metal Conduit) but thicker than EMT (Electrical Metallic Tubing) is IMC (Intermediate Metal Conduit). IMC is designed to provide a lighter-weight, lower-cost solution compared to RMC while still offering substantial physical protection and the ability to be used in many of the same applications. PVC, FMC, and ENT have different wall thicknesses and characteristics when compared to RMC and EMT, and they serve different types of installations and environmental requirements.